Influence of Nitrogen Fertilizer Application on Grain Yield, Nitrogen Uptake Efficiency, and Nitrogen Use Efficiency of Bread Wheat (Triticum aestivum L.) Cultivars in Eastern Ethiopia

Nano Alemu Daba

doi:10.5539/jas.v9n7p202

Abstract

The study was conducted in Eastern Ethiopia, namely Meta and Tullo districts, during the 2015 cropping season to determine the effect of N fertilizer levels on N uptake, N use efficiency (NUE) and grain yield on bread wheat cultivars. Factorial combinations of five N levels (0, 30, 60, 90, and 120 kg N ha-1) and four bread wheat cultivars (Danda’a, Digalu, Kakaba and local cultivar) were laid out as a randomized complete block design (RCBD) with three replications. The interactions of sites, N levels, and cultivars significantly (p ≤ 0.01) affected grain yield (GY), nitrogen uptake by grains, total nitrogen uptake, nitrogen uptake efficiency (NUpE) and nitrigen use efficiency for grain yield (NUEGY). Main effects of sites, N levels and cultivars had significant (p < 0.01) effect on grain and straw N contents, straw N uptake, N biomass production efficiency, N utilization efficiency (NUtE) and nitrogen harvest index (NHI). The cultivar Kakaba at rate of 90 kg N ha-1 produced the highest grain yield (4880 kg ha-1) in Tullo, which was statistically similar with the grain yield (4816 kg ha-1) obtained from the cultivar Digalu with 120 kg N ha-1 in Meta district. The NUEGY was higher with values of 24.2 and 24.1 kg grain kg-1 N in Tullo and Meta districts, respectively, for Digalu cultivar at 30 kg N ha-1 application rate than the remaining N levels and variety interactions at both sites. Cultivars variations in NUEGY under low N application levels were mainly due to higher variations in NUpE than in NUtE. Therefore, there is a need for exploration of the effectiveness of various combinations of N rates with time of applications for improvements of N-use efficiency traits and cost effectiveness in improved wheat cultivars production.

Highlights

Bread wheat (Triticum aestivum L.), which is used both as a source of food and income, is one of the most important cereal crops in Ethiopia
The results clearly showed that there was no significant differences among all wheat cultivars in the nitrigen use efficiency for grain yield (NUEGY) with increasing level of N from 90 to 120 kg N ha-1 in Meta district
This study has demonstrated that grain yields of the two improved bread wheat cultivars, Kakaba and Digelu, were maximized significantly with N application rates of 90 and 120 kg ha-1 in Tullo and Meta districts, respectively, compared to the other lower nitrogen treatment combinations

Summary

Introduction

Bread wheat (Triticum aestivum L.), which is used both as a source of food and income, is one of the most important cereal crops in Ethiopia. It is the fourth most widely grown crop after tef, maize, and sorghum (FAO, 2015). The amount of wheat produced is insufficient to meet the domestic needs, which is compelling the country to import about 25 to 35% of the annual wheat grain required for consumption (CSA, 2014). Declining of soil fertility is a major constraint for wheat production (Fageria, 2007); supply of adequate and balanced nutrients is one way of achieving high bread wheat grain yield (Kassahun, 2004)

Methods

Results

Conclusion